A controller including a first control member and a second control member that extends from a portion of the first control member. A controller processor is operable to produce a rotational movement output signal in response to movement of the first control member, and a translational movement output signal in response to movement of the second control member relative to the first control member. The first control member may be gripped and moved using a single hand, and the second control member may be moved using the thumb of the single hand.